NaEuF4 nano-/submicro-crystals with various morphologies including regular nano-spheres, submicrospheres, submicro-spindles and hexagonal submicro-rods were prepared through a facile hydrothermal process by adjusting the pH value and the molar ratio of Na(3)Cit/Eu3+ in the precursor solution. The resultants were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and photoluminescence spectroscopy (PL). The possible formation mechanisms for the morphology-varied NaEuF4 crystals were proposed based on the FE-SEM observation. The luminescent properties of NaEuF4 spheres with different particle size were studied. It was found that the luminescent intensities of NaEuF4 spheres increase with the decrease of particle size. Finally, the mechanism of luminescent enhancement was discussed. (C) 2014 Elsevier B.V. All rights reserved.